DE2012476A1 - Thermoforming device - Google Patents

Description

PATENT LAWYERS IN STUTTGART

U.S.Ser.No. 808,075

COMET INDUSTRIES, INC., Bensenville, Illinois, U.S.A;

Thermoforming device.-... · -.

The invention relates to a thermoforming device with an automatic Control device for controlling the work steps in a predetermined sequence using a programming device, in which a program carrier can be introduced, which in a The guide track of the programming device is movable and can be driven along this guide track by a drive.

One known type of thermoforming process uses plastics panels clamped to a frame and then heated. Included one part of the plastic plate can thereby be heated to a higher temperature than another part that a Template placed between the heat radiating heat source and the plastic panel during part of the heating period v / ird. ! times the heating, the plastic sheet is placed around a mold cavity held around and a pressure differential applied to the panel so that it is outwardly away from the cavity Plunger is arched too. After the plastic sheet is bulged too much for the plunger, the pressure differential is reversed, see above that the board now moves into the cavity of the mold, whereupon the plunger is pushed in, so as to help in the formation of the plastic object. The plunger is then removed and the molded object is cooled and removed from the hot

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molding facility removed.

In some of these "known thermoforming devices, the Time can be set for some of the work steps. For example, the duration of the heating on the plastic panel can be through a skilled operator can be adapted to the object to be molded. The heaters then remain for them Time period within the individual cycles of the hot forming device for forming the objects is set accordingly.

The known thermoforming devices and methods of control the same have the disadvantage that trained operators are necessary. This reduces the cost of the to be manufactured Items increases, and sometimes a bad product is created because the operator does not perform the operations optimally adjusts.

It is now known that some of these procedures can be performed without trained personnel to be controlled with the help of a recorded program, each containing a group of work steps, carried out one at a time within predetermined times should be. The programs are recorded on a tape or on cards that have magnetized parts or which have mechanical changes, for example incisions, perforations, projections or the like. The bands and cards are then constantly moved, and the magnetized ones Parts, perforations and protrusion ^, are made accordingly their order is scanned and used to control the machine.

This type of programming is for the control of '.varr.forr.- • devices not entirely satisfactory. The time it takes to perform some of the operations in the Y / arm form perform, for example, the time it takes to heat the

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Plastic panel is required, see changes according to a number of different conditions or state variables, for example the outside temperature of the room. As a result of ^one of these changes, the time required to perform a Arbeltsschrittes provide programs that -vorsehen a fixed time between steps, each step a process · who is terminated too soon or continues for too long when certain state variables are taken into account so that the result is a bad product. .

It is also known to use electronic computers which are able to make comparisons in order to control the devices which carry out certain process steps. These computers contain a program with reference values that define the time of the work steps. A state, for example the temperature or the position of the movable members in the one device for performing the method is measured and fed into the computer. The computer now compares the measured conditions with the recorded conditions, and the results of this comparison are now used to control the work steps in the device carrying out the method.

This type of device has the disadvantage that it is very is expensive. The computers themselves are expensive and require something learned Personnel for programming and operation. If trained personnel is required, so will the expense further increases, and it then often results in the same Way as with a manual control then a bad product, when the operators do not set the optimal conditions for the process steps.

The invention is therefore based on the task of providing a relatively 'cheap device for controlling hot forming processes.

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to create that take certain external conditions into account and which automatically carries out the work steps without being operated by specialists. This task is achieved in the aforementioned hot forming device according to the invention in that a Variety of Programmsehalterη is arranged by actuating elements of the program carrier can be actuated during its movement that a plurality of sensors in the hot-forming device for sensing state variables it is provided that a first one is connected to the program switches and / or sensors Control device is provided, which responds when the program switch and / or the sensor is actuated, and that a second with the program switches and the sensors connected control device is arranged to control the excitation of the drive the programming device is used.

According to the invention, conditions and states within the thermoforming machine can be measured, and the measurements of the same control the time of the process steps of a program.

Also in accordance with the invention is an improved programming device have been created for controlling the thermoforming machine, the programming device having a recording medium, on which a multitude of steps are recorded. Each step is capable of a process or a To control the working step of the hot forming device. The measurement of the conditions and states within the hot forming facility controls the duration of the steps.

In the programming device according to the invention, a plastic card is used which has a plurality of the above Plastic ribs with incisions at predetermined locations

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and which is driven by a drive motor parallel to the ribs is moved. There is a separate push-button switch for each individual rib provided, which is actuated at predetermined times by the incisions made there.

The individual push-button switches each control a different one Working process of the hot forming device. For example, a push-button switch moves the heating elements when pressed in a position above and below the plastic sheet. Another push-button switch energizes the heating elements to heat the plastic panel. Other! Functions of the hot forming equipment are similarly controlled by other pushbutton switches.

A large number of sensors are located within the thermoforming device intended. For example, a temperature sensor measures the temperature the plastic board, and limit switches feel the positions of the forming tools. Signals from the sensors are used to control further process steps and also to the To move the program card from position to position in steps. For example, the heating elements are via the temperature sensors switched off and at the same time switched on a drive motor that transports the program card so that it is now so moved far until another push button switch is actuated.

The program card is either stopped when a push button is pressed is actuated, or continues to move to one another separate push-button switches to operate one by one, the time interval being determined by the speed the driven program card is controlled. If the program card is stopped when a push button switch is operated is, bo it is set in motion again by one of the sensors of the thermoforming device. ■

009 338/1 £ 88

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The same thermoforming equipment is used to make a variety of different articles, and different ones Programs are required for some of the items.

Apart from the use of different program cards to control the thermoforming process of the individual objects other replaceable auxiliary devices are sometimes required. For example, a template on the top of a Heating grid can be arranged between the heating elements and the plastic sheet, so that the plastic sheet is different To heat temperatures in different areas. This template is only used in certain programs for certain objects is used, and a different template is used in other programs for other items. A stencil this type is conveniently stored with the program card with which it is used, until it is then needed will. The program card is then inserted into the programming device and the template into the hot-forming device introduced in order to participate in the shaping of the object in question.

This device for controlling a hot forming process is easy to implement and cheap. There are no skilled workers now necessary because the programs are prepared by the manufacturer of the hot forming equipment prior to the desired use on which the programs can then be stored. Hit this facility, the thermoforming machine working is perfect automatically and can be carried out entirely by non-specialists.

This programming technique does not require the use of a pre-match electronic computer, since the conditions within the hot-forming device do not match those stored in a computer Conditions are compared. The conditions

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and states are only felt to certain limits' to "determine, and when these limits are felt, so will the motor of the programming device is controlled accordingly. This makes the structure simpler than if a computer were used for the full control of the process can be used.

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Further advantages and features of the invention emerge from the following description in connection with the drawing, includes embodiments of the invention. In the drawing show:

Pig. 1 is a partially broken away front view of an embodiment of the invention;

Pig. 2 is an enlarged, exploded, partial perspective view of a heat grid trolley and a template, as in the embodiment according to the invention according to Pig. 1 can be used,

Pig. 3 is an enlarged front view of a Pro-r programming device. as in the embodiment according to the invention according to Pig.1 can be used,

Pig. 4 is an enlarged, perspective partial view of a base plate and a clamping device to explain a process stage of the process as it is through the embodiment is carried out according to Pig. 1,

Pig. 5 is an enlarged perspective view

a program card as used in the embodiment according to Pig. 1,

Pig. 6 shows a block diagram to explain the mode of operation of the embodiment according to Pig.1.

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In Pig. 1 Is a hot formingir I tang as a whole Mt 10 designated. This has a return station 12, a forming station K and a programming device 16. The hot forming device 10 is only used to explain the invention, but other hot-forming devices as shown in Pig.1 can also be used equipped with the invention.

The return station 12 has a frame in the form of a right-angled Parallelepipets with four vertical columns, two of which, 18 and 20, can be seen in Figure 1, and also four bottom struts, one of which at 22 in Fig.1 is shown. A hood 30 is held on the vertical columns above the return station 12 by angle pieces, two of which, 32 and 34, are shown in FIG.

Across the lower parts of both the return station 12. As well as the forming station 14, a vacuum tank 24 is arranged which has walls 25. Above the vacuum tank 24 there are two pairs of parallel rails arranged, namely rails 26 for the one carrying the upper heating elements Carriage and the rails 40 for the carriage carrying the heating grid. These rails extend across both the Return station 12 as well as over the JOrmstation 14 away. Inside the vacuum tank 24 is another pair of parallel rails 28 for the die.unteren heating elements supporting Carriages are provided which also extend across both the return station 12 and the forming station 14.

In order to heat a plastic sheet, a large number is required of lower heating elements 36 arranged on a movable Yfagen, which on the parallel rails 28 within the

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Vacuum tank 24 is slidable, and a plurality of upper heating elements 38 are on another movable cart mounted, which is movable on the parallel rail 26 within the hood 30. The pair of parallel rails 4-0 also carries a viagen 42 for a heat grille.

As can be clearly seen from Fig. 2, the V / heat grid carrying car 42 has a rectangular frame 48, the is movably arranged on the parallel rails 40 with the aid of four liners 50 and now between the interior the return station 12 and the interior of the forming station 14 can be moved back and forth with the aid of a lever 82 (FIG. 1) can. The bottom of the rectangular frame 48 is closed by a grid 52, which has such a large passage that the heat radiated from the upper heating elements 38 impinges on the plastic object through the grid which is held at the forming station 14 by a clamping device 46. Furthermore, a template 54 is provided, which has a relatively large impermeable portion 56 which is radiated from the upper heating elements 38 Blocked heat. Furthermore, the template 54 has a relatively permeable portion 58 through which the heat radiated from the upper heating elements 38 can pass therethrough. The stencil has such a size and shape, that it fits into the frame 48 and can be held on the grid 52 so as to control the distribution of heat, the plastic panel held in the plague jig 46 is emitted. These templates, such as the template 54, may have different open portions according to the molding process that is performed shall be,

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The plague jig 46 (see Pig. 4) has an outer Holding frame 60 which fits into an opening of the vacuum tank 24. Around a plastic panel 70 on the frame A rectangular inner tensioner frame is provided which is secured by a variety of air-actuated tensioners. 72 "is actuated on the outer circumference of the holding frame 60 are arranged, and have an air cylinder, 'which communicate with pneumatic lines.

As can be clearly seen from Pig. 2, it is a pneumatic one Cylinder unit 78 pivotable by a. Pin 80 arranged on lever 82. The lever 82 is on the lower floor strut hinged by a pin 84 and has a longitudinally extending slot 86 at its upper end on, which interacts via a pin with the carriage 42 carrying the heating grid in such a way that when the lever 82 through the cylinder unit 78 of the carriage 42 along the parallel rails 40 between the return station 12 and the Pormstation 14 is moved. Similarly, the Carriage for heating elements 36 and 38 between the return station 12 and the Pormstation 14 with the help of not shown, pneumatically operated cylinder aggregates moved.

The Pormstation 14 has a regular parallelepipet as Stand that has four towering pillars, one of which two, namely 20 and B8, are shown in Pig.1, the pillars 20 both being part of the frame of the return station 12 as well as the Pormstation 14 form. Similarly, the molding station 14 has four bottom struts 12, One of the bottom struts 22 can be seen in Pig. 1, with two bottom struts 22 common to the return station 12 and the Pormstation 14 are attached ". Four upper transverse

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struts 90 form the upper part of the frame, one of which is to be seen in Figure 1.

To now top and bottom molds 94 and 96 on top of each other to "move" towards or away from one another, four upwardly projecting racks 92 are provided, two of which are shown in FIG are. These are arranged between the transverse struts 90 and the bottom struts 22 of the forming station 14 and form a inner parallelepipet to support the upper and lower movable dies 94 and 96 of the forming station. The top and lower movable dies 94 and 96 are respectively arranged in an upper and lower support plate 98 and 100, respectively, the perpendicular along the racks 92 with the help of pinions 102 are movable. Furthermore, compressed air lines 104, one of which can be seen in FIG lower molding tools with compressed air sources so as to perform the molding operation.

In order to control the movement of the support plates 98 and 100, a vertical steering column 106 extends between the Bottom struts 22 and the upper yuerstreben 90 of the forming station 14 adjacent to the path of movement of the upper and lower support plates 98 and 100, and this vertical control column carries four limit switches 108, 110, 112 and 114. The limit switch 100 is at the top and limit switch 110 arranged at the lowest point of the movement path of the upper support plate 98. The operating arms of these two Limit switch v / earth operated by the support plate 98 to so the movement in the relevant upper or lower layers to stop. Similarly, the frontier chattel 112 is at the topmost SteJlc and the limit switch 114 at the bottom Ste]. "! <? The ju'v.'egungsbahn the lower support plate 100 arranged, so as to stop their movement.

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The programming device 16 has a "plastic" program card 116, which is shown in detail in FIG and 5 is shown. This card 116 has a variety of protruding ribs 118 made of plastic, the incisions women, and also the card has a central row of teeth 120. As can be clearly seen from FIG. 6, it engages in the row of teeth 120 of the program card 116 a pinion 124, which is of a Motor 122 can be driven. A variety of push button switches 126A to 126? are arranged within the programming device 16. The individual switches are with their operating buttons in line with one of the ribs 118 arranged so that the push button switches are selectively closed by the incisions when the program card 116 is driven by the motor 122. The push-button switches control different work processes in the V / arm forming device 10.

The. Programming device 16 and the program card 116 can for example, such as indicated by the "company Otto Ramstetter, Factory of Electrotechnical Apparatus, 8 MUn- * chen 25, Bruderhofs tr. · 28-30, to be sold »

The V / arm-forming device also has sensors to differentiate To control work processes. For example, there is a sensor (see Fig, 6) above the plastic sheet inside the forming station, which senses its temperature. When the temperature of the plastic sheet is a predetermined Has reached height, the sensor actuates an electromagnet in order to switch off the lower heating elements 36. In similarly control limit switches 108, 110, 112 and 114 · the limits of the movement of the lower and upper support plates 98 and 100, In addition, with the help of a light bar

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130 and 132 (see Pig. 4 and 6) the height of the plastic panel scanned from the Pormhohlraurn of the lower support plate 98 bulges out.

These sensors control work processes in the hot-forming machine and also the drive motor 122 of the programming device 16, so that this is now aie programmed 116 to carry out drives further program steps. How clearly 3 shows, the programming device 16 has a Insertion opening 123 into which the program card 116 plugged in v / ird. Furthermore, there is an end wall with a plurality provided by indicator lights 125 to indicate the work that has just been carried out. There are also others Indicator lights 127 attached to indicate the direction of movement on the program card.

How the

The procedure ^ un preparation for the manufacture of each different plastic objects each differs slightly according to the particular conditions, for example a different template 54 is used to make different parts of the plastic sheet 70 to soften, and another program card 116 is used to control the operations of other items, The program card uni the template are made together with an identification of the product stored for that ^ they are used in the manufacture, Üio then become Taken together from the warehouse if never needed.

To the mode of operation of a v / armJ'cniiseiivrrichtung according to the To explain the invention, the process steps in the

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Manufacture of a typical product course explained, but ' it should be noted that not all procedural steps are explained here. The work steps not explained in more detail however, they are known per se and otherwise differ from product to product.

At the beginning of the workflow, the selected template 54 placed on the grid 52 arranged in the carriage 42 within the frame 48, and the corresponding program card 116 is plugged into the programming device 16. Further a plastic sheet 70 is placed in the clamping device 46.

To start the process, the operator presses two * start buttons, so now the pneumatic Clamping devices 72 close and the motor 122 the The program card 116 can run along the guideway for the first incision of the ribs 118. When the first incision is reached, the first indicator lamp 125

* i er_

of the program device 16 is lit, so as to carry out the first method step to suggest. The progress of the program card 116 through the programming device 16 can then through the lighting of successive indicator lamps 125, the indicate the process step carried out in each case, and also by the position of printed characters on the Program card relative to a reference mark on the programming device to be tracked.

The first step programmed on the program card 116 is merely the step through which the Air pressure in the vacuum tank 24 is increased. In order to

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step, an incision in one of the ribs 118 of the program card 116 is moved until it actuates an actuating button of the pushbutton switch 1262, which closes a circuit through which an air tank control 146 is energized so as to put the vacuum tank 24 under pressure The program card 116 is now moved until two more incisions actuate the operating buttons of the pushbutton switches 126A and 1263, which turn on the heating element control 134 and the grid control 136 and move the carriage 42 with the template 54, and which also activate the upper heating elements 38 and move and energize the lower heating elements 36. The pushbutton switch 1263 operates, in addition to moving the grid, a stop control 138 _{which turns off the I / O} gate 122 of the programming device 16. This stops the movement of the program card 116.

While the plastic panel 70 is now being heated, controls the light barrier 130, 132 (Fig. 4) the air pressure in the vacuum tank 24. When the beam of the light source 130 interrupted is before it reaches the photocell 132, namely because the plastic panel / is correspondingly bulged, so the Air pump stopped. If the jet is not interrupted, the pump starts to supply 24v compressed air to the vacuum tank to feed.

After the temperature of the plastic has reached a predetermined Has reached the limit, the V / heat sensor 126 actuates the starter control 140 in order to bring the fcotor 122 up and running again. At the same time, the grid control 136 becomes retractable of the grid is energized, then in front of the heating elements 36 and 38 to be withdrawn and shut down *

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This sequence of steps shows two ways in which the programming device with the Y / arm molding machine according to the invention cooperates. The first two process steps are performed with a predetermined time interval performed by moving the program card 116. the The program card was doing this at a constant speed driven by the motor during these two process steps so as to control the duration of these two working steps. The next step, however, was conditioned by the temperature of the plastic sheet and could therefore not be used after a predetermined time to the previous process step. As a result, the program card stopped while the Heating elements continued to heat the plastic panel after a heat sensor has sensed that the synthetic tablet has a has reached a predetermined temperature, the programming devices restarted by this Viärmefühler and the heating elements switched off. From this program sequence it results that the programming device directly controls the time between two method steps, or it take on state variables within the varmforming processes the timing of the programming device and also the Performing some of the process steps in the hot forming process.

The program card 116 now continues its movement after the start-up made via the heat sensor 128 until a Cut the actuator button of the push button holder 126D actuated, which now excites the following four units:

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1. The air tank controller 146 to control the supply of compressed air to stop the vacuum tank 24,

2. the air tank controller 148 to apply vacuum to the vacuum tank 24, causing the plastic panel 70 to move downward in the mold cavity is drawn in,

3. the upper support plate control 150 to start the movement of the upper support plate downwards, whereby the plunger of the upper support plate penetrates the mold cavity of the lower support plate, and

4. the lower platen control 142 to guide the mold cavity to move upwards in the lower support plate.

As the top deck moves down, it interacts with the actuator arm of limit switch 110 (Figures 1 and 6) which in turn energizes the top deck control to stop the top deck from moving down. Similarly, the limit switch 112 stops the movement of the lower support plate (not shown in Figure 6). In the meantime, the program card 116 continues to move until at a later point in time an incision passes under the actuator button of the pushbutton switch 126F, which in turn excites the upper support plate control 150, so that the upper support plate now begins to move upwards . As the top deck moves up, it cooperates with the actuator arm of limit switch 108 (see Figures 1 and 6) which in turn actuates top deck control 150 to stop the top deck from moving in the upward direction.

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The above-mentioned sequence of work steps shows the converging control by the programming device and through the elements of the thermoforming device. For example, the motor 122 starts the program card at the same time to move forward inde ^ the upper support plate has started in the downward direction. The support plate is through a disconnected limit switch stopped while the program card 116 is still moving forward. To a A further push-button switch within the programming device is activated at a predetermined later point in time the program card 116 actuated in order to move the upper support plate back up into the end position. In summary it can therefore be said that the programming device initiates a work step that is preceded by an external Control is stopped while the program card is still in motion. Yes, the process of a predetermined further During this period, the program card starts up the workflow again in a different direction. The working sequence is thus simultaneously controlled by a sensor, namely the limit switch, and by the programming device 16 controlled.

The program card continues to move and an incision goes through under the push button switch 126C, the the cooling control 142 energizes so as to cool fans and not Steam spray system shown for cooling the plastic panel 70 to start. Further, not shown push button switches are operated by the program card to so to break the vacuum in the vacuum tank 24 and to eject it to put the deformed plastic sheet under pressure, and to later lower the lower support plate and open the clamping device.

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As a result, the programming device and the V / arm forming device are simple and operate economically. Moreover, the method of manufacturing V / arm molded articles by this facility can now be carried out without those skilled in the art and can be carried out with a level of reliability that was previously not achievable with relatively cheap equipment was. The program card and other special parts, such as the templates, can be stored for as long as you like and can then be used by unskilled workers to re-create items just right, even if the operator has never made these items before.

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Claims (1)

A 38 061 h - 21 - May 16, 1970 Claims Warning forming device with an automatic control device to control the work steps in a predetermined sequence using a programming device> into which a program carrier can be introduced, which is in a guideway the programming device is movable and can be driven along this guide track by a drive, characterized in that that a plurality of program switches (126) are arranged along the guideway and can be actuated by actuating elements of the program carrier (116) when it is moved; that a plurality of sensors (108, 110, 112, 114, 128) in the thermoforming device for Sense of state variables is provided that a first with the program switches (126) and / or sensors (108, 110, 112, 114, 128) connected control device is provided, which when actuating the program switch (126) and / or the Sensor (108, 110, 112, 114, 128) responds, and that a second with the program switches (126) and the sensors (108, 110, 112, 114, 128) connected control device is arranged to control the excitation of the " drive (122) of the programming device (16) is used, Thermoforming device according to claim 1, characterized in that that at least one of the sensors is a limit switch (108, 110, 112, 114). Thermoforming device according to claim 1 or 2, characterized in that that at least one of the sensors is a heat sensor (128). Thermoforming device according to one of the preceding claims, characterized in that the program carrier (116) has actuating elements arranged in rows (118). Thermoforming device according to claim 51, characterized in that that for the timing of the various parts of the warm - 22 - 009838/1969 A 38 061 h - 22 - h-24
March 16, 1970 form device (10) separate actuating elements are provided. 6. Thermoforming device according to one of the preceding claims, characterized in that the arrangement is made so that a program switch (126) actuated by an actuating element carries out a working step of the warning device (10) starts up and a sensor (128) stops it when actuated. 7. thermoforming device according to any one of claims 1-5, characterized characterized in that the arrangement is such that a sensor (128), when actuated, triggers a working step of the arm shaping device (10) starts up and a program switch (108, 110, 112, 114) stops it when it is actuated. 8. hot-forming device according to one of the preceding claims, characterized in that the first control device for starting and stopping a work step includes control elements which can be controlled via program switches (126) and / or sensors (108, 110, 112, 114, 128). 9. Thermoforming device according to one of the preceding claims, characterized in that the second control device controls to stop the drive (122) of the program carrier (116) when a program switch (126) is actuated and for starting this drive (122) when one of the sensors is actuated ( 108, 110, 112, 114, 128). 10. A thermoforming apparatus according to one of the preceding claims, characterized in that a heat screen (52) supporting drivable V / agen (42) is provided, whose drive (78) via the first control device by closing one of the program switch (126) and / or the sensor (108, 110, 112, 114, 128) can be actuated. 11. Thermoforming device according to claim 10, characterized in that the plastic blank to be deformed (70) on the carriage - 23 - BATH ORIGINAL 009038/1969 A 38 061 h - 23 - 2Ö12476 h-24 ■ ■ '■ March 16, 1970 (42) can be clamped and heating elements (36, 38) for raw
warm the plastic piece (70) are provided. 12. hot forming device according to claim 10 or 11, characterized characterized in that the carriage (42) with the heat grille (52) is controllable so that during at least part of the Working cycle the plastic blank partially against heating, is shielded. 13. Hot forming device according to claim 11 or 12, characterized in that that the excitation of the heating elements (36, 38) can be controlled by the programming device (16). 14. Thermoforming device according to one of claims 11-13 »characterized characterized in that the clamping of the plastic blank (70) by the programming device (16) is controllable. 15. Thermoforming device according to one of the preceding claims, characterized in that two molding tools (94, 96) are provided with at least one mold cavity. 16. hot forming device according to claim 15 »characterized in that that the movement of the molding tools (94 »96) can be controlled by the programming device (16). 17. Thermoforming device according to claim 15 or 16, characterized characterized in that to control the movement of the form-r tools (94, 96) limit switches (108, 110, 112, 114) are provided are. 18. Warmforraeinrichtung according to one of claims 15-17, characterized characterized in that a pressurized gas source is present which, when a limit switch (108, 110, 112, 114) - with the mold cavity for bulging out the plastic blank (70) is connectable. ...: ■■. "■■ - - 24— 009838/1969 A 38 061 h - 24 - March 16, 1970 19. Thermoforming device according to claim 18, characterized in that a light barrier (130, 132) for sensing the Bulge is provided. 20. Thermoforming device according to claim 19, characterized in that the light barrier (130, 132) with a sensor switch cooperates. 21. Thermoforming device according to claim 20, characterized by dadv.rch, that the first and second control devices control elements for starting a drive motor (122) of the programming device (16) and for switching off the pressurized gas source when this sensor switch is closed. 22. Thermoforming device according to one of claims 15-21, characterized in that the first control device a control element for moving the one molding tool (94) designed as a ram into the mold cavity of the other Has molding tool (96) when closing a further sensor. 009838/1969